Variable-speed transmission



March 27, 1951 M, FRAZER 2,546,856

VARIABLE-SPEED TRANSMISSION Filed Sept. 27, 1949 2 Sheets-Sheet l MarionR. Frazier ATTORNEYS.

March 27, 1951 M. R. FRAZIER 2,546,355

VARIABLE-SPEED TRANSMISSION Filed Sept. 27, 1949 2 Sheets-Sheet 2 I02 nFig. 6

E? 2 Marion R. Fi'azier ATTORNEY S.

Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE VARIABLE-SPEEDTRANSMISSION Marion R. Frazier, Bellevillc, N. 3.

Application September 2'21, 1949, Serial No. 118,052

lil Ciaims.

This invention relates to variable speed transmissions and moreparticularly to such mechanisms employing expansible pulleys consistingof conic portions.

An important object of the invention is to provide a mechanism of thiskind in which the pitch diameters of the pulleys are manually varied bymeans of a minimum of parts, none being complicated, and the mechanismmay be readily disassembled for replacement of parts in the field.

Another important object is to provide a mechanism as described in whichthe conic portions float on their respective shafts and are under springtension.

Still. another important object is to provide, in

a mechanism of this kind, including V-belts, resilient means for thepurpose stated above whereby the conic portions are axially shiftahlefor positive alignment with the respective l-belts.

A further important object is to provide the springs mentioned forfunctioning additionally to minimize vibrations of the V-belts duringoperation.

Another important object is to provide a floating assembly of conicportions, making up expansible pulleys, and their shaft arranged forrunning the pulleys on a common substantially horizontal axis at alltimes, thus obviating any tendency of the pulleys from hanging ontheV-belts.

Furthermore, an additional important object is to provide these springsand their associated parts of the mechanism for maintaining aparticularly close alignment between the driving and driven members soas to minimize wear and stress on the V-oelts.

Included in the new variable speed transmission is a rack and pinionassembly, and an ob-- ject of the invention is to provide resilientmeans to prevent creepage between the rack and pinion during operationof the mechanism.

Another object of the invention is to provide for hand wheel adjustmentof the conic portions of the mechanism wherein there is a new andpositive means to secure the hand wheel in an rotative position so thatthe pinion, move ab e only upon rotation of the hand wheel, is fixedagainst accidental rotation.

Other objects and advantages of the invention will be apparent duringthe course of the following detailed description of the invention,

taken in connection with the accompanying drawings, forming a portion ofthis disclosure, and in which drawings:

Fig. i is a perspective view of one embodiment oi"; the new variablespeed transmission mounted upon a horizontally disposed, fiat support,and by way of example, operatively associated with a prime mover and adriven mechanism.

Fig. 2 is a vertical longitudinal section of the transmission of Fig. 1.

Fig. 3 is an end elevation (right-hand end of Fig. 2) of the newtransmission of Figs. 1 and 2 with the conic portions and hand wheelremoved.

Fig. l is a perspective view of another embodiment of the new variablespeed transmission associated, by way of example, with a verticallydisposed tubular support, a prime mover and a driven mechanism.

Fig. 5 is a vertical section of the variable speed transmission of Fig.4 but disclosin also mechanism common to both forms.

Fig. 6 is a fragmentary transverse section (with some portions in plan)of the transmission of Figs. 4 and 5.

Fig. 7 is a partly broken away elevation of the hand wheel assemblycommon to both forms.

Fig. 3 is a transverse section (enlarged) substantially on the line 8-8of Fig. 5.

In the drawings, wherein for the purpose of illustration are shown twoforms of the invention, and wherein similar reference charactersdesignate corresponding parts throughout the several views, the letter Adesignates one form or the new variable speed transmission; B, anotherform thereof; C and D, two types of supports therefor; E and F primemovers; G and H driven mechanism; a drive belt and L a driven belt.

The new variable speed transmission A and B each have many portions oftheir structure in common, since each includes a plurality of pulleyscomprising, in the example shown, three conic portions It, H and i2,with the outermost portions iii and i2 substantially alike, andproviding portions of two pulleys, with the portion l 5 formin theadditional portion of both pulleys.

Each portion l6 and i2 has an outwardly-extending hub is and aninwardly-extending, pulley flange i i extending from the hub and havingan inclined face 95 providing one-half of a pulley groove. At the baseportion of the flange is a circumferential groove l6 extending towardthe hub lit and, extending from the groove it toward the rim ii of theflange i l, are spaced-apart teeth is which, of course, fall short ofthe rim ii. The portions l9 and i2 are disposed spaced apart and withthe teeth of one projecting toward the teeth of the other.

The central or intermediate conic portion Ii,

comprises an outwardly-extending huh 2t and a upon an outer hollow,longitudinally-iecipro- 3 cable shaft having a smooth cylindrical outerperiphery.

Means to adjustably secure the two conic portions iii and I2 to theshaft 30 may be the Walls of a screw-threaded bore 36 extending from theouter periphery of each hub It to its inner periphery and a set screw Blcarried thereby and bearing against the shaft 36.

Means to slidably secure or key the conic portion ii to the shaft maythe walls of a longitudinally-extending slot ll in the shaft to with itsends spaced a substantially equal distance from each end of the shaft,and a pin or key 42 extending into the slot ll and carried by theportion l l, as by having its screw threaued base portion screwed into asuitable screw threaded, radially-extending bore extending from the rim2G to the inner periphery of the conic portion ll.

inwardly of and spaced from the shaft 35 is a hollow,longitudinally-reciprocable shaft preferably substantially as as theshaft 3 and reciprocabie therewith.

Bearing means 55 between. the shafts til and all may be spaced-apartball bearing races, inwardly of the ends of the shafts and with theirouter rings in engagement with spaced-apart abutments extending from theinner peripher of the shaft 33 outwardly of the slot ll.

inwardly of the shaft is a spindle 55 on which the shaft 45 is slidablymounted. The spindle extends outwardly of the shaft t5 and has adisc-coupled end portion 53 and a moving block-supported end portion5'5.

A central shaft 6E3 extends through and outwardly beyond the spindle 55and may be spaced therefrom as by suitable bearings 6! which arepreferably disposed at the end portions 56 and 5'3. It has a handwheel-carrying end portion 62 and pinion-carrying end portion 63.

The hand wheel assembly 55 comprises a suitable hand wheel 56,associated disc at and means 65 to couple the hand wheel 56 and disc 5?.The latter is carried in a suitable recess 69 in the inner face of thehand wheel 56. The mean 38 may be the walls of a plurality of equallyspacedapart concavities l, in the recess-facing side of the disc 5?,spaced an equal distance from its center, adapted to receive a portionof a suitable number of bal s H (such as four balls disposed in andprojecting from spaced-apart concavities in the walls of the base of therecess 59. I Means [5 to detachably secure the hand wheel 56 to thecentral shaft may be a set screw '45 bearing against the end portion 62and extending through a screw-threaded, radially-extending bore 77 inthe hand wheel wall.

Means 38 to secure the disc Bl to the spindle 55 may be solder, such assilver solder at the end portion 56 of this spindle.

All of the structure described is preferab y common both forms the invenion, and s milar reference characters are employed, up to this point, inboth forms to desi nate like parts.

Referring now particularly to Figs. 2 and 3, the end portion 5'! of thespindle 55 may be secured to a movable block or bracket 85 which has abore 36 to accommodate this end portion 57 as well as the pinioncarrying end portion 53 of the central shaft and a resilient means $5 tobe subsequently described. The spindle 55 may be detachably secured tothe block 85 as by key means 8? comprising a screw threaded key 83extending through a suitab e radial opening in the spindle 5%": (in asnug fitting relationship) and a screw we u 3 threaded bore extendingthrough the block 85 to the bore 86.

Mounted upon the free end of the portion 63 where it projects from theblock 85, is a pinion 9 5 which may be detachably coupled to the portion83 as by set screw means 9i comprising a set screw extending through aradially-extending screw threaded bore in the pinion 9%.

This pinion 9G meshes with the teeth of an arcuate rack extending from abracket arm 96. Looking downwardly upon the teeth, the rack is convex.The arm 55 is carried by a base Bl from which also extends (parallelingthe arm 9%) a pivot pin accommodating bearing 98 carrying a pivot pin 99which extends through the leg portion itll of the block 35 whereby theblock may be moved in an arcuate path but is not movable longitudinalyof the transmission A. The base 9? may be detachably secured to asuitable support as the support C, as by bolts mi.

Referring now to the important resilient means which are common to bothforms A and B and could not be well described without initial referenceto the block and the pinion, there is provided resilient means H35 toprevent creepage of the pinion 9 with respect to the rack 95, andcomprising an expansion spiral spring with one end bearing against thepinion 953 and the other end bearing against the end portion 57 of thespindle 55, thus attempting to force the central shaft Eli to the rightin Fig. 2 but this tends to forcethe hand wheel 65 tightly against thedisc El which is immovable longitudinally of the spindle 55 and thelatter is also immovable longitudinally since it is keyed to the block85 by the means Bl. This affords a good friction brake against theundesirable creepage mentioned. I have found that each of the springs ofthe means 35 may be of .062 music wire, formed into six coils, having afree length, when spiralled, of substantially one inch and an exteriordiameter of 78 inch.

The other resilient means i it permits the conic portions to float ontheir respective shafts, under spring tension, so that they are axiallyshirtable for positive alignment with the respective V-belts. This meansHi3 also minimi es vibrations of the v-belts during operation as well asprevents the conic portions from hanging on the belts. In addition, themeans Ht tends to cause closer alignment between the driven. and drivingmembers, preventing undue wear and stress on the belts. The means ill!comprises two expansion spiral springs, one hearing at one end againstthe disc 5! (which thus pr rides an abutment) and against the innermostring of one ball bearing race of the means 58, while the other expansionspiral spring of the means Ht bears at one end against the innermostring of the other ball bearing race and bears, at its other end againsta suitable abutment as a washer HI mounted on the spindle 55 preferablyclosely adjacent the inner end of the block 85 and held in place by aslip ring H2 fitted into a suitable peripheral groove in the spindle 55.By way of example, I have found that a spring of .074 music Wire, formedinto eleven coils, having a free length, when spiralled, ofsubstantially 1 inches and an exterior diameter of 4% inch is desirablefor the spring 8 it.

The form 3 contemplates a movable block or bracket M5 to which the endportion 51 of the spindle 55 be secured. This block I it has a bore MEto accommodate the end portion 5? as well as the pinion-carrying endportion 63 of the central shalt 5t and the resilient means i5.

The spindle 55 may be detachably secured to the block H5 as by key meansIII (like the means 81) comprising a screw threaded key I I8 extendingthrough a suitable opening in the spindle 55, and a screw threaded boreextending through the block to the bore I I6.

In the form B, the pinion I2!) is preferably larger in diameter than thepinion 90 but, like it, it is mounted on the free end of the portion 63as by a set screw means I2 I.

The teeth of the pinion I meshes With the teeth of a rack I22 (bestshown in Fig. 8) carried by a bracket arm I23. Viewed with the bracketarm substantially horizontal (as in Fig. 4) the rack is longitudinallyinclined from the vertical (substantially as in Fig. 8)

The arm I23 is carried by a half ring base I24, there being a secondhalf ring base I25 so that the two may be detachably coupled as by thescrew means I26 in order to clamp the two at a a suitable tubularsupport D.

The base I25 also carries an arm I21 paralleling the arm I23 with theinner faces of the arms in face contact.

Means to permit movement of the block I i5 as the pinion I 20 moves overthe inclined rack I22 may be a pair of tongues I 3| extending outwardlyof the block H5 in opposite directions and extending into suitablegrooves I32 in the arm I21, while the other portions of the block withinthe arms I23 and I21 are accommodated in suit-- able inclined slots I33and I34 respectively.

It will be noted that the walls of groove I32 include two suitable coverplates I35 secured to the arm I27 as by screws I35 which also areemployed to secure the arm I23 to the arm I21 since their shanks I3?extend into both arms. This permits detachment from the bracket arms ofthe block H5 after removal of the pinion and loosening of the means II1.

In both forms A and B, the row of teeth of each rack is inclined bothfrom the vertical and horizontal.

In Fig. 1 the new variable speed transmission A is operativelyassociated with a prime mover E, as an electric motor, through the driveV-belt K which is trained over a pulley I38 mounted upon the motor shaftI3! and trained over the expansible pulley represented by the conicportion I0 and facing part of the conic portion I I. Over the expansiblepulley, represented by the conic portion I2 and the facing part of theconic por tion I I, is trained a driven v-belt L which is also trainedover a pulley I35 of a driven mechanism G.

In the case of the variable speed transmission B of Fig. 4 for example,the same is clamped to the tubular support D, employing the bracket I23I21, and operatively associated with a prime mover F by means of a V-beltK trained over a pulley I40 mounted upon the shaft I4I of the motor, andthis belt as well as the belt L are associated with the transmissionmechanism B exactly like the similar belts are associated with thetransmission mechanism A. The belt L is trained over a pulley I of thedriven mechanism H of Fig. 4.

Manual rotation of the hand wheel assembly of either form A or B willcause the entire mech anism (minus the brackets, except the bracket orheads and IE5) of either form A or B to move toward or away from theprime mover E or F, as the case may be and, consequently, move away fromor toward the driven mechanism G or H, as the case may be. Thesemovements are compensated for by longitudinal movements of the conicportion iI, along the shaft 39, whereby the distances of those portionsof the belts K and L (trained over the expansible pulleys) from the axisof rotation of the conic portions Ill, II and I2 will be increased ordecreased, as the case may be, thus effecting variations in the speed oftransmission of power to the driven mechanisms. When a desired speed issecured, the operator can release the hand wheel, knowing that thedistances of the mechanism of A or B from their associated prime moversand driven mechanisms Will remain fixed, until again manually altered.

The two springs of the resilient means I It are, of course,substantially alike and provide with the shaft 3%, for a floatingrotative support for the expansible pulleys, while the conic portion IIis readily shiitable with respect to the portions It and I2, such asfrom the position in full lines to the position shown in dots and dashesin Fig. 5. (This latter position is shown in full lines in Fig. 6.)

The connection of the hand wheel I56 and disc 6'! through the medium ofthe balls II and walls of their sockets It and i2 permits the operatorto pull outwardly upon the hand wheel 66 when he desires to rotate it,thereupon permitting the balls II to ride out of the sockets i0 and thusdetach the hand wheel from the disc which is fixed against rotation.When the balls are within their sockets, the hand wheel cannotaccidentall rotate. Normally, the hand wheel is drawn toward the disc 61by the resilient means I I15 as stated.

Various changes may be made to the forms of the invention herein shownand described without departing from the spirit of the invention orscope of the claims.

What is claimed is:

1. In a variable speed transmission, a longitudinally-reciprocablehollow shaft; a plurality of expansible pulleys mounted thereon, eachcomprising an outer portion and a section of an intermediate portionnext adjacent to the outer portion, each outer portion having abelt-contacting face and the intermediate portion having twobelt-contacting faces, one facing one of said first faces and the otherfacing the other of said first faces, whereby two pulley grooves areprovided; means securing the outer sections to said shaft in spacedapart relationship with said faces there-- of in facing relationship;means securing said intermediate portion to said shaft to slidelongitudinally thereof; ball bearings, comprising races having inner andouter rings, for said shaft; a V-belt for each expansible pulley withportions of said belts in said grooves; a pair of abutments normallyspaced outwardly from the outer ends of said shaft a substantially equaldistance; and means for yieldably resisting moving said shaftlongitudinally upon wedging pressure of one of said belts against abelt-contacting face of either of said outer portions, including amember inwardly of said shaft, mounting said bear-- hogs and slidablewith said shaft, a pair of expansion spiral springs with. one like endof each bearing against the innermost rings of said bearings and theother like end of each bearing against said abutments, said innermostrings being mounted directly upon said member and said outermost ringsbeing in peripheral contact with the inner periphery of said hollowshaft.

2. In variable speed transmission, a fixed support; a movable supportcarried thereby; a rigid spindle mounted upon said movable support andprojecting therefrom; means carried by said fixed support for guidingsaid movable support in a path inclined from the vertical andhorizontal; a shaft rotatably and longitudinally slidably carried bysaid spindle; expansible pulleys operatively-mounted upon said shaft;and manually-perable means to permit movement of said support in saidpath, including a pinion fixed to said spindle and a rack fixed to saidfixed support, said rack having a row of teeth with the row inclinedfrom the vertical and horizontal.

3. In variable speed transmission, a fixed support; amovable supportcarried thereby; a rigid spindle mounted upon said movable support andprojecting therefrom; means carried by said fixed support for guidingsaid movable support in a path inclined from the vertical andhorizontal; a shaft rotatably and longitudinallyslidably carried by saidspindle; expansible pulleys operatively mounted upon said shaft;manually-operable means to permit movement of said support in said path,including a pinion fixed to said spindle and a rack fixed to said fixedsupport, said racx having a row of teeth with the row longitudinallyarcuate.

i. In variable speed transmission, a fixed support; a movable supportcarried thereby; a rigid spindle mounted upon said movable support andprojecting therefrom; means carried by said fixed support for guidingsaid movable support in a path inclined from the vertical andhorizontal; a shaft rotatably and longitudinally slidably carried bysaid spindle; expansible pulleys operatively mounted upon said shaft;manually-operable means to permit movement of said support in said path,including a pinion fixed to said spindle and a rack fixed to said fixedsupport, said rack having a row of teeth with the row longitudinallycurved.

5. In variable speed transmission, a fixed support; a movable supportpivotally carried then by; a rigid spindle mounted upon said movablesupport and projecting therefrom; means carried by said fixed supportfor guiding said movable support in a path inclined from the verticaland horizontal; a shaft rotatably and longitudinally slidably carried bysaid spindle; expansible pulleys operatively mounted upon said shaft;manually-operable means to permit movement of said support in said path,including a pirion fixed to said spindle and a rack fixed to said fixedsupport, said rack having a row of teeth with the row longitudinallycurved.

6. In variable speed transmission, a fixed support; a movable supportslidably carried thereby; a rigid spindle mounted upon said movablesupport and projecting therefrom; means carried by said fixed supportfor guiding said movable support in a path inclined from the verticaland horizontal; a shaft rotatably and longitudinally slidably carried bysaid spindle; expansible pulleys operatively mounted upon said shaft;manuallyoperable means to permit movement of said support in said path,including a pinion fixed to said spindle and a rack fixed to said fixedsupport, said rack having a row of teeth with the row inclined from thevertical and horizontal.

7. In a variable speed transmission, a fixed support including anelongated bracket provided with a transversely extending slot, inclinedfrom the vertical and horizontal, and a groove opening into said slotand inclined from the vertical and horizontal; a movable block carriedwithin said slot and having a tongue extending into said groove, saidslot and groove being longer than the width of said block; a rigidspindle carried by said block and projecting therefrom and outwardly ofsaid slot and fixed support; a shaft within said spindle and rotatableand slidable therein; expansible ipulleys operatively mounted upon saidshaft; manually-operable means carried partly by said shaft to permitmovement of said [block along saidslot and said tongue along saidgroove; and means cooperating with said manually operable means toreleasably retain said block at predetermined locations along said slot.

8. In a variable speed transmission, a fixed support including anelongated bracket provided with a transversely extending slot, inclinedfrom the vertical and horizontal, and a groove openinginto said slot andinclined from the vertical and horizontal; a movable block carriedwithin said slot and having a tongue extending into said groove, saidslot and groove being longer than the width of said block; a rigidspindle carried by said block and projecting therefrom and outwardly ofsaid slot and fixed support; a shaft within said spindle and rotatableand slidable therein; expansible pulleys operatively mounted upon saidshaft; manually-operable rack and pinion means to permit movement ofsaid block along said slot and said tongue along said groove; and meanscooperating with said manually operable means to releasably retain saidblock at predetermined locations along said slot.

9. In a variable speed transmission, an outermost hollow,rotatable andlongitudinally reciprocable shaft; expansible pulleys mounted thereon; asecond hollow rotatable and longitudinally reciprocable shaft within andspaced from the first shaft; bearings between the two shafts; a spindleextending through the second shaft; a movable support for the spindle; afixed support for the movable support; a floating connection between thespindle andbearings; and means to permit movement of said shafts,pulleys, bearings, spindle, connection and movable support, as a unit,in a path inclined from the vertical and horizontal, said path beingnormal to the longitudinal axis of said shafts and spindle.

10. In a variable speed transmission, an outermost hollow, rotatable andlongitudinally reciprocable shaft; expansible pulleys mounted thereon; asecond hollow rotatable and longitudinally reciprocable shaft within andspaced from the first shaft; bearings between the two shafts; a spindleextending through the second shaft; a movable support for the spindle; afixed support for the movable support; a floating resilient connectionbetween the spindle and bearings, and means to permit movement of saidshafts, pulleys, bearings, spindle, connection and movable support, as aunit, in a path inclined from the vertical and horizontal, said pathbeing normal to the longitudinal axis of said shafts and spindle.

MARION R. FRAZIER.

REFERENCES GI'EED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,152,207 Needham Mar. 28, 19392,186,477 Coddington, J an. 9, 1940 2,235,122 Shaw 1- Mar. 18, 19412,253,921 VanSant Aug. 26, 1941 2,293,230 Waltz Aug. 18, 19 12 FOREIGNPATENTS umber Country Date 170,115 Great Britain Mar. 29, 1921

